Cylindrical combination lock



July 22, 1947-, B. sTiERNER 4 CYLINDRICAL COMBINATION LOCK Filed June 8, 1958 ,mening BERNARD STERNR Patented July 22, 1947 CYLINDRICAL COMBINATION LOCK Bernard sternenAntwerp-Berchem, Belgium Application June 8, 1938, Serial No. 212,548 In Belgium May 28, 1938 Section 3, Public Law 690, August 8, 1946. Patent expires May 28, 1958 s claims. (o1. ro-ass) The invention relates to a cylindrical combination lock and in particular to a lock of .theV kind having pushers which are movable longitudinally in a revoluble cylinder and are displaceable against spring action by bits of adjustable length` provided on a key to be inserted in the lock. The pushers are capable of being coupled with combination members which are displaceable longitudinally in a Xed part of the lock and are hereinafter termed tumblers, in order to bring them into a position corresponding to the combination of the key and they may be disconnected from those tumblers by a rotation f the abovementioned cylinder in order to block this cylinder by placing themselves between said tumblers during the withdrawal of the key.

In a known cylindrical lock of this kind the above-mentioned pushers are each provided with two coupling members which are integral with lateral projections which are guided in longi-` tudinal slots cut out in the revoluble cylinder. For the purpose of coupling, these members are adapted to engage in corresponding notches provided in each' of said tumblers. This construction and arrangement of said parts of the lock has the disadvantage that the combination with which the lock has been locked may be `detected by feeling the tumblers by means of a tool in-l serted through the hole of the lock or by means of the pusher itself.

An object of the invention is to obviate this disadvantage and to ensure the position of the tumblers of the lock being perfectly safe against detection by touch, by giving the lock a conformation such that on the one hand no insertion of a tool across said longitudinal slots in order to reach the tumblers is made possible and on the other hand it is impossible to detect the position of the tumblers by feeling them laterally by means vof the coupling members of the pushers, taking advantage of any play which may exist between these coupling members and the combination members.

Another object of the invention is to provide a lock constructed so that whatever may be the position of a pusher, the inside of the revoluble cylinder affords no break in continuity between the keyhole opening of the lock and said lateral projection of the pusher.

For this purpose said pushers are formed by U-shaped pieces the branches of which are joined by said lateral projections guided in said longitudinal slots. One branch, namely the internal branch, is guided in a, longitudinal keyway axially provided in said revoluble cylinder and the other branch, namely the external branch, is guided on the outside of said cylinder. The latter branch carries at its ends the coupling members between which a tumbler places itself when it is coupled to the pusher.

Another object of the invention is to provide a lock having U-shaped pushers the internal branches of which are of such a length that the free ends thereof facing the keyhole opening of the lock always block said keyway, thus creating an obstruction to the passage of a tool towards said longitudinal slots of the revoluble cylinder.

Another object of the invention is to provide a lock having U-shaped pushers the external branches of which are of such a length that said `external branches of the pushers when depressed form obstructions barring access from said longitudinal slots of said revoluble cylinder to saidrtumblers. In this manner said U-shaped pushers when depressed always close from outside and from inside the portion of said longitudinal slots which extend between the fore end thereof and said lateral projections joining the two branches of each pusher, whereby any passage from the keyway of the lock to th'e tumblers is prevented.

Another object of the invention is to provide a lock having U-shaped pushers the internal Y branches of which accommodated side by side in a central axial keyway `of the lock have each a transverse section such that, when juxtaposed, they form together a body which entirely fills the above-mentioned axial keyway.

Another object of the invention is to prevent advantage being taken of any play which may exist between the coupling members and the tumblers, by sliding the pushers along the tumblers and causing them to bear laterally against the latter, whereby the position of the tumblers, and thus the combination employed to lock the lock might be ascertained. For this purpose said tumblers are, according to the invention, provided on their lateral longitudinal flanks with `grooves the width of which corresponds to that by feeling the tumblers with the coupling members of the pushers and on the other h'and they allow the coupling members to engage with these grooves, arresting the pushers in positions which do not allow of verifying whether they corres 3 spond to the combination with which' the lock has been locked.

Other characteristics and advantages of the new lock will be clear from the following description taken in conjunction with the accompanying drawing, which represents, merely by way of example, one form of construction of a lock in accordance with the invention.

In the drawing:

Figure 1 is a longitudinal section through the new lock on the line I-I of Figure 2, the parts being shown in the neutral position, for the sake of clarity only one pusher and one tumbler are illustrated.

Figure 2 is a transverse section on the line II-II of Figure 1. g

Figure 3 is a section similar to that of'Figure 2 but on the line III-III of Figure 1.

Figure 4 shows a longitudinal section of the lock in an axial plane passing through two pushers which have been moved back by the bits of the key which arefof different length and which are disconnected from the tumblers by rotation of the internal cylinder.

Figure 5 is a perspective View of a tumbler coupled with its pusher.

The same reference numerals denote the same parts in the various figures of the drawing.

The cylindrical combination lock represented in the drawing comprises essentially a, xed external cylinder I, a revoluble internal cylinder 2, movable pushers 3 which are guided longitudinally in the internal cylinder 2 and are displaceable against the action of the springs 4 by the bits 5 of adjustable length (Figure 4) of a key, and tumblers 6 which are displaceable in longitudinal grooves 'I of the fixed external cylinder I. The above-mentioned pushers 3 are adapted to be coupled by a rotation of the cylinder 2 to th'e tumblers 6 in order to bring each of them into a position dependent upon the length of the bit which has displaced the corresponding pusher.

To this end said pushers are provided with coupling members protruding on the outside 0f the revoluble cylinder 2 across longitudinal slots I9 cut out in said cylinder. These slots are opened towards the end of th'e inner cylinder remote from the keyhole opening thereof and extend towards the fore end of the said cylinder over a distance which is necessary to allow Vthe pushers to be moved from one extreme position to the other in the lock.

A rotation in the one direction or the other which is then imparted to the internal cylinder 2 releases the pushers 3 from the tumblers 6 which remain blocked in the position into which they have been carried, while the pushers 3 return under the action of their springs 4 towards the keyhole opening of the lock 8 when the key is withdrawn and dispose themselves between the tumblers and prevent any rotation of the cylinder 2.

In order to prevent detection of the combination with which the lock has been locked by feeling the tumblers by means of a tool being introduced through the keyhole opening 8 of the lock, all the pushers are accommodated in a single keyway 9 which is axially provided in said revoluble cylinder and the individual pushers are so shaped that, when placed one beside another,

they t together and form a polygonal prism which lls the keyway 9 entirely. In the example illustrated in the drawing the lock comprises six pushers each of triangular section and forming together a hexagonal prism which'ts the section of the keyway 9. Furthermore, the pushers 4 3 are of a length such that even when they are' pushed into their most advanced position (Fig. 4) their front ends I 0 are still lying inside the uninterrupted portion of the keyway 9 adjacent to the keyhole opening and block the bottom end of it, so` that the tumblers 6 and their guide grooves 'I in the external cylinder are inaccessible from the outside of the lock.

In order still further to increase safety of the lock, each pusher 3 forms part of a U-piece and of which it forms the internal branch which is lldisposed in the keyway 9 and is joined by a bridge branches pushers.

piece II to a longitudinal member I2 which forms the external branch of said U-shaped piece. This external branch I2 is adapted to slideon the external face of the cylinder 2 and carries coupling noses I3-I3' adapted to coact posed between the noses I3-I3.

The bridge piece II is adapted to move in the slot I9 of the cylinder 2.

The springs ll acting on the U-shaped push'ers are positioned in said slots I9 and bear against the bridge pieces II.

The external branches I2 of the pushers 3 are also of a length which is such that their front ends, namely the noses I3, are always applied on the external face of the cylinder 2 beyond th'e closed end of said longitudinal slots I9 (Figure 4) In this way the path which a tool has to take from the keyhole opening 8 of the lock to a groove 'l is furthermore of winding form and would render impossible the passage of such tool. The I2 are accommodated entirely in grooves I4 of the internal cylinder 2 in such a manner that only their noses I3-I3 are outside the cylinder. In this manner, when the internal cylinder 2 is blocked and an attempt is made to turn it, the torsion is transmitted from the internal cylinder 2 directly to the noses I3 and I3 over the whole length of the branches I2 of the III areadvantageously of dovetail form (Fig. 5) which renders the accuracy of the working of the branches I2 independent of the guiding of the pushers 3 and prevents them moreover from separating radially and engaging with the external cylinder.

The external branches I2 of the pushers have a width which is equal or substantially equal to that of the tumblers 6 (Figure 5). The latter, and therefore also their guide grooves 'I in the external cylinder I are of dovetail form which prevents them from sliding radially out of the external rcyilnder.

v`In order to block the tumblers 6 in the position into which they have been moved by the lI3 provided on each movable tumbler 6 when -the cylinder 2 yis rotated. The projections I5'alymost entirely ll the space between two branches This has the advantage that the bridge,

. I2 of the pushers so that even a slight rotation of the cylinder 2 (Fig. 2) xes the tumblers 6 in their position at the moment.

The end of the revoluble cylinder 2 is attached by suitable means to a bolt or the like to be actuated by the cylinder lock.

It has been found that it is possible to detect by touch the point where the coupling noses of the pushers reach the ends of the tumblers 6 by sliding these noses I3 and I3 along the combination members and pressing' them against the flanks of the latter taking advantage of any play which allows of a slight rotation of the cylinder 2.

In order to prevent the discovery of the combination `with which the lock has been locked by detecting in the manner described the position of the tumblers 6, in accordance with the invention, said tumblers are provided on their flanks with a plurality ofgrooves I8 arranged parallel to one another and having a width corresponding to that of the coupling noses I3-I3. The position and the number of these grooves and also the distance between two adjacent grooves may be different on the two flanks of the tumblers f6. The presence of the grooves I8 distributed asymmetrically in the flanks of these tumblers will baiile and mislead any person who endeavours to detect the combination of the lock by manipulating the pushers of the lock.

The rotating internal cylinder 2 may be displaced into three determined positions, namely two end positions in which the pushers 3 andthe combination members 6 are angularly displaced relatively to one another, so that when the key is withdrawn the internal cylinder 2 is prevented from rotating, and a third position intermediate between the two above-mentioned end positions in which the pushers 3 and the tumblers 6 are coupled and from lwhich position the internal cylinder 2 may be turned towards one or the other end position with any desired adjustment of the adjustable bits:

The lock according to the invention functions in the following manner.

When the lock has been brought into its neutral position (Figs. l, 2 and 3) a key, the bits 5 of which have been adjusted according to a desired combination is introduced into the keyway 9.

Each pusher and at the same time the tumbler 6 which being lodged between the noses I3 and I3' of the external branch I'2 is thereby coupled to this pusher are moved together by an amount corresponding to the length of the bit which actuates the pusher in question. The amount of this displacement may if desired be different for each tumbler (Fig. 4). During the subsequent rotation of the key, and therefore of the internal cylinder 2, towards the one or the other of its two end positions, the noses I3 and I3 disengage the tumblers 6, and at the same time the segments I5 of the internal cylinder 2 engage in the teeth I' of the tumblers 6 and X the latter in the position into which they have been brought by the pushers 3.

During the removal of the key, the pushers 3 all return into their initial position under the action of their springs 4, so that their noses I3 and i3 take position between the tumblers 6. The latter thus prevent any angular displacement of the pushers 3 and accordingly of the internal cylinder.

From this position the cylinder can be brought into the intermediate neutral position or beyond the latter into the opposite end position only if the key employed for this operation possesses the same setting of the bits as the key which had previously been used for bringing the lock from its intermediate neutral position into the iirst end position. If a key with a different adjustment is introduced and an attempt be made to rotate the internal cylinder 2 by means of that key, the noses I3 and I3' of the pushers 3 and the tumblers S remain displaced relatively to one another in the axial direction of the lock and prevent any rotation of the cylinder 2.

The three above-mentioned positions of the internal cylinder 2 may be intended in practice for the operation of a closing device, for` example, the two end positions being employed to allow of unlocking and locking this device and the intermediary neutral position for altering the combination of the lock.

Having now particularly described and ascertained the nature of my invention and in what manner the same is to be performed, I declare that what I claim is:

1. A cylindrical combination lock to be locked by a combination key having longitudinally adjustable bits and to be unlocked only by a key of identical Combination of bits comprising in combination two cylinders arranged concentrically one inside the other, the outer cylinder being xed, the inner cylinder being rotatably mounted and provided axially with a longitudinally extending keyway opened towards the keyhole of the lock, pushers slidably accommodated side by side in said longitudinal keyway and depressed by the bits of the key when inserted in said keyway, springs actuating said pushers so as to i'mpell them towards the keyhole opening of the lock, parallel longitudinal slots cut out in said rotatable cylinder, said slots being opened at the end of said cylinder remote from the keyhole of the lock and having a length less than the length of said cylinder, radial projections laterally provided on said pushers and protruding outwardly of said rotatable cylinder across said longitudinal slots, grooves longitudinally provided in said fixed cylinder, tumblers slidably arranged in said grooves, coupling means provided on said lateral projections for connecting said pushers and tumblers for a common longitudinal movement, whereby said tumblers are moved by action of said couplingmeans into positions corresponding to the combination bitting selected, means for disconnecting said pushers from said tumblers when in said positions, means for locking said rotatable cylinder against rotation by cooperation of said pushers and tumblers, means for locking said tumblers from movement when disconnected from said pushers and means for preventing the position of said tumblers when locked from being detected by aid of means inserted from inside of said rotatable cylinder into the longitudinal slots thereof when the pushers are depressed.

2. A cylindrical combination lock to be locked by a combination key having longitudinally adjustable bits and to be unlocked only by a key of identical combination of bits comprising in combination two cylinders arranged concentrical- 1y one inside the other, the outer cylinder being xed, the inner cylinder being rotatably mounted and provided axially with a longitudinally extending keyway opened towards the keyhole opening of the lock, pushers slidably accommodated side by side in said longitudinal keyway and depressed bythe bits of the key when inserted in said key- Way 'springs actuating said pushers so as to imopening thereof and having a length less than the length of said cylinder, radial projections laterally provided on said pushers and protruding outwardly of said rotatable cylinder across said longitudinal slots, grooves longitudinally providedin said fixed cylinder, tumblers slidably arranged iny said grooves, coupling means provided on said lateral projections for connecting said pushers and tumblers for a common longitudinal movement, whereby said tumblers are moved by action of said coupling means into positions correspond,

ing to the combination bitting selected, means for disconnecting said pushers from said tumblers when in said positions, means for locking said rtatable cylinder against rotation by cooperation of said pushers and said tumblers, means for locking said tumblers when disconnected from said pushers and means for screening on both ktheir sides said longitudinal slots between the closed ends thereof and said radial projections of said pushers when depressed.

3. A cylindrical combination lock to be locked by a combination key having longitudinally adjustable bits and to be unlocked only by a key of identical combination of bits comprising in combination an outer cylinder, an inner cylinder concentrically positioned in said outer cylinder, said outer cylinder being xed, said inner cylinder being rotatably mounted with respect to said outer cylinder and provided axially with a longitudinally extending keyway opened towards the keyhole opening of the lock, pushers slidably accommodated side by side in said longitudinal keyway and movably depressed by the bits of a key when inserted in said keyway, springs actuating said pushers so as to impell them towards the keyhole opening of the lock, parallel longitudinal slots cut out in said rotatable cylinder, said slots being opened at the end of said cylinder remote to the keyhole opening and having a length less than the length of said cylinder, radial projections laterally provided on said pushers and protruding outwardly of said rotatable cylinder across said longitudinal slots, grooves longitudinally provided in said outer cylinder, tumblers slidably arranged in said longitudinal grooves of said outer cylinder, coupling means for connecting said pushers and tumblers for a common longitudinal movement, whereby said tumblers are moved by action of said coupling means into positions corresponding to the combination vbitting selected, means for disconnecting said pushers from said tumblers when in said positions, means for locking said rotatable cylinder against rotation by cooperation of said pushers and said tumblers, means for locking said tumblers when disconnected from said pushers and longitudinally extending members provided on said radial projections of-said pushers and slidably guided in the direction of said longitudinal slots on the outside of said rotatable cylinder, whereby U-shaped tumbler actuators are formed with parallel branches joined by said radial projections and having their free ends directed towards the keyhole opening end of said rotatable cylinder, said U-shaped actuators being of such a length and width that when depressed they overlap on both their sides said longitudinal slots between the closed ends thereof and said lateral projections of said pushers.

4. A cylindrical combination lock to be locked by a combination key having longitudinally adv justable bits. and to be `unlocked only by a key of .identical combination of bits comprising in combination an outer cylinder, an inner cylinder concentrically positioned in said outer cylinder, said outer cylinder being xed, said inner cylinder being rotatably mounted with respect to said outer cylinder `and provided axially with a longitu- :,dinallyy extending keyway opened towards the keyhole opening of the lock, pushers slidably accommodated side by side in said longitudinal keywayL and movably depressed by the bits of a key, :wheninserted in said keyway, springs actuating said-pushers so as to impel them towards the keyhole opening of the lock, parallel longitudinal Y slots cut out in said rotatable cylinder, said slots being `opened at the end of said cylinder remote to the keyhole and having a length less than the length of said cylinder, a radial projection laterallyv provided on the end of said pushers remote to the keyhole opening of the lock and protruding outwardly of said rotatable cylinder across a longitudinal slot thereof, grooves longitudinally provided in said outer cylinder, tumblers slidably arranged in said longitudinal grooves of said outer cylinder, coupling means for connecting said radial projections and tumblers for a common longitudinal movement, whereby said tumblers are moved by action of said coupling means into positions corresponding to the combination bitting selected, means for disconnecting said coupling means from said tumblers when in said positions, means for locking said rotatab-le cylinder against rotation by cooperation of said coupling means --and said tumblers, means for locking said tumblers when disconnected from .said pushers, a longitudinally extending'member provided on said radial projection of each pusher and slidably guided in the direction oi said longitudinal slots on the outside of said rotatable cylinder7 whereby U-shaped tumbler actuators are forme-d with parallel branches joined by said radial projections and having their free ends directed towards the keyhole opening end of said rotatable cylinder, said U-shaped tumbler actuators being of such a length and width, that when depressed thel7 overlap on both their sides said longitudinal slots between the closed ends thereof and said lateral projections of said pushers, said coupling means being carried by the branches 0f said U-shaped tumbler actuators extending on the outside of said rotatable cylinder.

5. A cylindrical combination lock to be locked by a combination key having longitudinally adjustable bits and to be unlocked only by a key of identical combination of bits comprising in oombination an outer cylinder, an inner cylinder concentrically positioned in said outer cylinder, said outer cylinder being iixed, said inner cylinder being rotatably mounted with respect to said outer cylinder and provided axially with a longitudinally extending keyway opened towards the keyholeof the lock, pushers slidably accommodated side by side in said longitudinal keyway and movably depressed by the bits of a key when outwardly of said rotatable cylinder across a longitudinal slot thereof, a longitudinally extending member provided on said radial projection of each pusher and slidably guided in the direction of said longitudinal slot on the outside of said rotatable cylinder, whereby U-shaped actuators are formed with parallel branches joined by said radial projections and having their free endsdirected towards the keyhole opening end of said rotatable cylinder, said U-shaped actuators being of such a length and width that when depressed they overlap on both their sides said longitudinal slots between the closed ends thereof and said lateral projections of said pushers, grooves longitudinally provided in said outer cylinder, tumblers slidably arranged in said longitudinal grooves of said outer cylinder, coupling means provided on the said U-shaped actuators branches extending on the outside of said rotatable cylinder for connecting said actuators and tumblers for a common longitudinal movement, whereby said tumblers are moved by action of said coupling means into positions corresponding to the combination hitting selected and for disconnecting said coupling means from said tumblers when in said positions by a rotation of said rotatable cylinder, means for locking said rotatable cylinder against rotation by cooperation of said coupling means and said tumblers, `means for locking said turnblers when disconnected from said U-shaped actuators, said coupling means consisting of noses radially provided at opposite ends of said U- shaped actuators external branches and separated by a distance equal to the length of said tumblers, so that said tumblers when connected to said U-shaped actuators are engaged between said coupling means.

6. A cylindrical combination lock to be locked by a combination key having longitudinally adjustable bits and to be unlocked only by a key of identical combination of bits comprising in combination an outer cylinder, an inner cylinder concentrically positioned in said outer cylinder, said outer cylinder being fixed, said inner cylinder being rotatably mounted with respect to said outer cylinder, and provided axially with a longitudinally extending keyway opened towards the keyhole of the lock, tumblers slidably arranged in longitudinal grooves provided in said outer cylinder, parallel longitudinal slots cut out in said rotatable cylinder, said slots being opened towards the end thereof remote from the keyhole and having a length less than the length of said cylinder, U-shaped tumbler actuators slidably arranged in said rotatable cylinder and movably depressed by the bits of a key when inserted in said keyway, said U-shaped actuators having their free ends directed towards the keyhole opening end of said cylinder, said U-shaped tumbler actuators having each an internal branch and an external branch joined by a cross-piece movable in a longitudinal slot of said cylinder, the internal branches of said U-shaped actuators being slidably accommodated side by side in said keyway and having each a cross section so shaped that when juxtaposed, they completely lill said keyway, the external branches of said U-shaped tumbler actuators being slidably guided in the direction of said longitudinal slots on the outside of said rotatable cylinder, said inner and external branches of said U-shaped tumbler actuators being of such a length that when depressed, they overlap on both their sides said longitudinal slots between the closed ends thereof and said cross pieces of said tumbler actuators, coupling means provided on said external branches for connecting said actuators and tumblers for a common longitudinal movement, whereby said tumblers are moved by action of said U-shaped actuators into positions corresponding to the combination bitting selected and for disconnecting said actuators from said tumblers when in said positions, means for locking said rotatable cylinder against rotation by cooperation of said coupling means and said tumblers, means for locking said tumblers when disconnected from said U-shaped actuators and springs positioned within said longitudinal slots of said rotatable cylinder, so as to bear on said cross pieces of said U-shaped tumbler actuators between both branches thereof.

7. A cylindrical combination lock to be locked by a combination key having longitudinally adjustable bits and to be unlocked only by a key of identical combination of bits comprising in combination an outer cylinder, an inner cylinder concentrically positioned in said outer cylinder, said outer cylinder being xed, said inner cylinder being rotatably mounted with respect to said outer cylinder and provided axially with a longitudinally extending keyway opened towards the keyhole of the lock, tumblers slidably arranged in longitudinal grooves provided in said outer cylinder, parallel longitudinal slots cut out in said rotatable cylinder, said slots being opened towards the end thereof remote from the keyhole and having a length less than the length of said cylinder, U-shaped tumbler actuators slidably arranged in said rotatable cylinder and movably depressed by the ,bits` of a key, when inserted in said keyway, said U-shaped actuators having their free ends directed towards the keyhole opening end of said cylinder, said U-shaped tumbler actuators having each an internal branch and an external branch joined by a cross-piece movable in a longitudinal slot of said cylinder, springs positioned within said longitudinal slots of said rotatable cylinder, so as to bear on said cross pieces of said U-shaped tumbler actuators between both branches thereof, whereby said tumbler actuators are impelled towards the keyhole opening end of said inner cylinder, the internal branches of said U-shaped actuators being slidably accommodated side by side in said keyway and having each a cross section so shaped that when juxtaposed, they completely ll said keyway, the external branches of said U- shaped tumbler actuators extending parallel to said internal branches in the direction of said longitudinal slots on the outside of said rotatable cylinder, said inner and external branches of said U-shaped actuators being of such a length and width that when depressed, they overlap on both their said longitudinal slots between the closed ends thereof and said cross pieces of said tumbler actuators, coupling means provided on said external branches for connecting said actuators and said tumblers for a common longitudinal movement, whereby said tumblers are moved by action of said U-shaped actuators into positions corresponding to the combination hitting selected, and for disconnecting said actuators from said tumblers when in said positions, means for locking said rotatable cylinder against rotation by cooperation of said coupling means and said tumblers, means for locking said tumblers when dis-l connected from said U-shaped actuators and longitudinal dovetailed grooves provided on the Outside of said rotatable cylinder for slidably guiding said external branches of said U-shaped tumbler actuators, said grooves having the depth equal to the thickness of said external branches, so that 11 only4 said coupling means areprojectinglout 'of said inner cylinder.

8.' A `cylindrical combixriation lock to be flocked bya combination key having longitudinallyadjustable bits and to beunlocked only by akey of identical combination of'bitscomprising in combination an outer cylinder 'having' longitudinal grooves,` an inner cylinder concentrically positionedV in said outer cylinder'havingiperipheral longitudinal grooves and, saidouter cylinder being xed, said inner cylinder being rotatably mounted with respect to said outer cylinder' and provided axiallyV with a longitudinally 'extending keyway openedtowards the keyhole of the lock; tumblers slidably arranged vin` said longitudinalY grooves provided -insaid outer cylinder, parallel'longitudinalslots cut out in said rotatable cylinder, spring pressed `U -shaped tumbler actuators slidably arra'nged in 'said rotatabler cylinder vandmbvably depressed bythe bits of a key, 'when inserted insaidkeyway againstthe spring actionysaldI U- shaped'tumbler actuators having each an internal branchiand an external branch joined'by across-4 piece 'movable inv a longitudinal slotl of `said cylin'i der, the internal branches Aofsaid U'shaped actuators being slidably accommodatedside by side'in said keyway'and having feach a cross sectionlr so shape'dthat when juxtaposed,they completely ll said keyWay, the'external branches' of saidU- shaped tumbler actuators extendin'giparallelto said'internal branches in the direction of said lon.V gitudinal-slots land slidablyvguided on tliev outside in` said peripheral longitudinal grooves provided in said rotatable cylinder, said inner and external 12 branches' of=said U'shaped tumbler actuators being'-ofsuchalength and Width that when depressed, 'they overlap on both-their sides said longitudinalfslots between the closed ends thereof and said cross'fpieces of said tumbler actuators, coupling noses provided on said external branches and! adapted 'to' receive said tumblers between them'forcnnecting said actuators and said tumblers" forl aA common longitudinal movement, whereby said 'tumblers are moved by action of said Ulshaped actuators 'into positions corresponding toth'e'co'mbination bitting selected and for discoririect'r'igA said actuators from said tumblers Whenin 'said `positons, means for locking said rotatablecylinder vagainst rotation by cooperation of saidfcouplng noses and said tumblers, means forlocking'said'tumblers when disconnected from said-'coupling noses and notches provided ontumblers a'nks constacting said longitudinal grooves in'saidouterfcylinder, said notches extending parallel to said coupling noses of said U-shaped actuators'fandhavingthe same Width as said noses.

BERNARD S'IERNER.

REFERENCES' CITED Theffllowiiigreferences are of record in the leof 'this' patent:

UNITED STATES PATENTS Number Name Date 1,819,853'y Von Mehren Aug. 18, 1931 2,024,534 I LejbOWCZ June 16,' 1936 1,036,764 WlSOIl Allg. 27, 1912 

